Thank you for contacting our support.
Sitefinity relies on a technique for creating web pages that dynamically adapt to any form factor called Responsive design. At it’s core, responsive design relies on a CSS3. Therefore every browser that covers CCS is supported by Sitefinity. It is said that about 80% of today's devices support this responsive design. All dominant mobile browsers on their platform like Android, iPhone, WP8, Blackberry, Opera, etc., also support this.
Sitefinity does not support mobile browser detection out-of-the-box. However you can inspect a server variable from the HTTP request to detect this. See this example for more information:
I hope this helps.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items